Received-SPF: pass (google.com: domain of linux-kernel+bounces-20106-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.48.161 as permitted sender) client-ip=147.75.48.161;
From: =?UTF-8?q?N=C3=ADcolas=20F=2E=20R=2E=20A=2E=20Prado?= <nfraprado@collabora.com>
To: Mark Brown <broonie@kernel.org>
Cc: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>,
	kernel@collabora.com,
	=?UTF-8?q?N=C3=ADcolas=20F=2E=20R=2E=20A=2E=20Prado?= <nfraprado@collabora.com>,
	Jaroslav Kysela <perex@perex.cz>,
	Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>,
	Liam Girdwood <lgirdwood@gmail.com>,
	Matthias Brugger <matthias.bgg@gmail.com>,
	=?UTF-8?q?N=C3=ADcolas=20F=2E=20R=2E=20A=2E=20Prado=20via=20Alsa-devel?= <alsa-devel@alsa-project.org>,
	Rob Herring <robh@kernel.org>,
	Takashi Iwai <tiwai@suse.com>,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org,
	linux-mediatek@lists.infradead.org,
	linux-sound@vger.kernel.org
Subject: [PATCH] ASoC: mediatek: mt8192: Check existence of dai_name before dereferencing
Date: Mon,  8 Jan 2024 17:44:58 -0300
Message-ID: <20240108204508.691739-1-nfraprado@collabora.com>
Precedence: bulk
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Following commit 13f58267cda3 ("ASoC: soc.h: don't create dummy
Component via COMP_DUMMY()"), the dai_name field is only populated for
dummy components after the card is registered. This causes a null
pointer dereference in the mt8192-mt6359 sound card driver's probe
function when searching for a dai_name among all the card's dai links.

Verify that the dai_name is non-null before passing it to strcmp. While
at it, also check that there's at least one codec.

Reported-by: "kernelci.org bot" <bot@kernelci.org>
Closes: https://linux.kernelci.org/test/case/id/6582cd6d992645c680e13478/
Fixes: 13f58267cda3 ("ASoC: soc.h: don't create dummy Component via COMP_DUMMY()")
Signed-off-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>

---

 sound/soc/mediatek/mt8192/mt8192-mt6359-rt1015-rt5682.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/sound/soc/mediatek/mt8192/mt8192-mt6359-rt1015-rt5682.c b/sound/soc/mediatek/mt8192/mt8192-mt6359-rt1015-rt5682.c
index 5bd6addd1450..bfcb2c486c39 100644
--- a/sound/soc/mediatek/mt8192/mt8192-mt6359-rt1015-rt5682.c
+++ b/sound/soc/mediatek/mt8192/mt8192-mt6359-rt1015-rt5682.c
@@ -1208,7 +1208,8 @@ static int mt8192_mt6359_dev_probe(struct platform_device *pdev)
 			dai_link->ignore = 0;
 		}
 
-		if (strcmp(dai_link->codecs[0].dai_name, RT1015_CODEC_DAI) == 0)
+		if (dai_link->num_codecs && dai_link->codecs[0].dai_name &&
+		    strcmp(dai_link->codecs[0].dai_name, RT1015_CODEC_DAI) == 0)
 			dai_link->ops = &mt8192_rt1015_i2s_ops;
 
 		if (!dai_link->platforms->name)
-- 
2.43.0